Freelance Photographer
Durham, UK

Posts Tagged ‘testing’

Canon Lens Auto Focus Accuracy – Part 2

Sunday, August 21st, 2011

Having set my mind at rest in Part 1 that my new lens wasn’t totally dodgy, I set about trying to make it even better.  In fact, I decided to repeat the process on all three of my main lenses. (more…)

Canon Lens Auto Focus Accuracy – Part 1

Sunday, August 14th, 2011

Back in May I wrote about the new Canon 70-200mm f4 L IS lens I had chosen and my reasons for making the choice I did.  After taking it out on a few non-critical sessions I haven’t been blown away by its sharpness – it’s good, but perhaps not quite as crisp as I was hoping for.  I started wondering if this was down to my unrealistic expectation or if there was something wrong with the lens.

Then one day I was out on the riverbanks in Durham and saw a heron fishing in the shallows.  I was a bit far away, but thought I’d grab a few frames just for interest.  Reviewing the shots I’d just taken zoomed in on the camera’s LCD, the heron was clearly blurred even though I was absolutely certain I had auto-focused on the body (I was too far away to pick up the eye which I would normally aim for).  What was more, the detail in the background was sharp – and it was consistent, shot after shot.  Suddenly I panicked – did my new lens have a serious back-focus problem?

Grey Heron

The shot that started it: after default sharpening in Capture One, this Heron still looked soft while background details look sharp (100% crop)

(more…)

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